The primary objective of this research is to develop new technology to characterize personal exposure to airborne metals in the workplace. The secondary objective is to improve upon the state-of-the-art in both sensitivity and time-resolution of airborne metals exposure assessment. Key to this effort is an innovative technology called microfluidic paper analytical devices (5PADs) that integrate sampling with analysis in a low cost, high sensitivity format. Our central hypothesis is that 5PADs can be integrated into personal aerosol samplers for quantification of personal exposure to airborne metals with sampling and analysis times of less than one hour. To test this hypothesis, we propose the following specific aims: (1) Construct a single-analyte microfluidic paper analytical device (5PAD) for metal analysis that is compatible with existing, size-selective personal aerosol samplers;(2) Construct a multi-analyte 5PAD for analysis of Pb, Cu, Mn, and Ni concentrations in air;(3) Validate the performance of the multi-analyte 5PAD in the field. Successful completion of the above aims will provide industrial hygienists with a sensitive, in-situ technique to assess airborne metal hazards in the workplace. Such technology represents a paradigm shift in the field of exposure assessment, as it has the potential to replace the traditional practice of sample shipment and laboratory analysis (both of which are time and resource intensive) with a direct, field analysis technique with improved sensitivity and time-resolution. This research contributes to the National Occupational Research Agenda (NORA) by developing a new and inexpensive instrumentation (a cross-sector theme) for assessing worker exposure (a cross-sector theme) to airborne metals (affecting the transportation/utilities, manufacturing, and construction sectors). Chemical analysis of a 5PAD sample is expected to be at least an order of magnitude less expensive (around 5$ per sample) than analysis with traditional ICP-MS or AES techniques. Furthermore, integrating the 5PAD into existing aerosol sampling devices (i.e., inhalable filter samplers) will enhance its acceptance by practicing occupational health professionals. This technology may open the door to a new realm of aerosol exposure assessment, as 5PADs can be adapted to detect and quantify many metal, organic, or inorganic compounds. PUBLIC HEALTH RELEVANCE: The primary purpose of exposure assessment is to identify and prevent workplace conditions likely to cause injury and disease. Exposure assessment methods rely on the ability to make quantitative measurements of health hazards with little or no uncertainty, an assumption that is lacking for many emerging respiratory hazards in the workplace (e.g., beryllium, cadmium, and engineered nanoparticles). The sampling technology proposed here (5PAD) will help reduce this uncertainty by providing industrial hygienists with detection limits low enough to make informed decisions on protecting worker health and by aiding occupational epidemiologists in the detection of respiratory diseases without a proportionate increase in exposure assessment costs.